Process of making nitrated superphosphate.



UNITED STATES nn-r oFFroE.

JOHANNES SCHLUTIUS, OF KAROW, GERMANY.

PROCESS MAKING NITRATED .SUPERPHOSPHATE.

Specification of Letters Patent.

Yatented. Dec. 3', 1907.

Application filed January 3. 1906. Serial No. 294.348.

many,have invented certain new'and useful- Iin rovements in Nitrated Superphosphate an. Processes of Making Same; and I do hereby declare the following to be a full, clear,

and exact description of the invention, such as Wlll enable others skilled in the art to which it %ppertains to make and use the same ites) always possess he subject of my invention is a process of manufacturing a material rich in nitrogen and phos horns and the application of the same for ertilizing purposes.

Hitherto phos hates as they occur in nature have generally been rendered soluble by treatment with sulfuric acid,'whereby they are converted into soluble 'm'onocalcium phosphate and g 'psum, an oldprocess, first described by Lie 1g. The procedure underlying this treatment varies, depending upon the chemical composition of the particular phosphate} it may, however, in expressedby the equation c rp, 21sec, CaH P,Og+ 2caso,.

This method of efieoting solubility, however, can not be regarded as a rational one, either from a chemical or economical standpoint. Chemically regarded it is not a perfect one, since the native phosphates (the phosphora certain percentage of iron and alumina, w hichbind part of the sulfuric acid forming acid reacting sulfates which are highly objectionable in the soil. When phosphates rendered soluble by the said treatment are kept for long, or even in' the soil, a certain reversion of the phosphoric acid takesplace, which must either be tolerated, or must be obviated during the solvent trcatment by the use of excess of sulfuric 5 acid. The reversion 'of the phosphoric acid involves loss of available phosphoric acid, or at any rate it retards the fertilizing action, while excess of sulfuric acid incurs unneces-' sary expense and numerous other disadvantagcs. Economically viewed, the said. process is still more lrrational. The reversion of the phosphoric acid, or excess of sulfuric acid, is in itself an eccnomical drawback, but

this nevertheless may: )0 regard ed as comparatively sllght comparec with the great economical drawback that gypsum is formed as a I comparatively worthless by-product. The sub ect ormy :nvention 1s a process whereby general be these serious losses are avoided. The principle of the same is, thatthe lime separated from its compound with phos horic acid by the solvent treatment, is combined with another material possessing fertilizing properties, in such manner that this compound This can be done with particular advantage by binding with nitric acid and other exidation roducts of nitrogen. In rendering soluble y means of nitric acid, nitrate of lime is formed instead of gypsum; and at the same time the'iron andalumina contained in the phosphorites are combined with nitric acid and thus converted into carriers of nitrogen, that is to to say, into plant-foods.

Taking nitric acid as exemplificatory of the gen, the chemical changes under] -ng the process may be expressed by the ollowing equation:

08. 130, eHNO, can r o +2Ca(N0.'3)2

The-advantage of this manner of rendering soluble is, that all the bases contained in the phosphorites, whether bases of calcium, iron, aluminium or other element, are combined products, or such as can not be utilized in the soil, or only indirectly so,

The rocess is especially advantageous in view of the fact that nitric acid and other the solvent treatment have, of late, been obtained more cheaply than hitherto from salt peter, by oxidation of the nitrogen of the air.

This use of products of oxidation, is, as it l were, to convert atmospheric nitrogen into a l manure rich in nitrogen and phosphorus.

The treatment with nitric acid and other products of the oxidation of nitrogen is par I ticularly advantageous in the case of those 2 phosphorites which on account of their high percentage of iron and alumina, have been 5 regarded as of little or no value; for according to the new process the iron and alumina constituents are also converted into useful carriers of nitrogen.

Having thus described my invention, what l I claim as new and desire to secure by Letters f Patent is,

likewise becomes a food-carrier for the plants.

as is obvious; nor any other insoluble or byl behavior of the oxidation products of nitrowith acids which are carriers of the important T oxidation products of nitrogen necessary for 1. The process of preparing a fertilizer which consists in oxidizing atmospheric nitrogen to form nitric acid and other products of oxidation and reacting upon a native phosphate containing iron and alumina With sufficient of such products to decompose the contained tricalcium phosphate and to combine with basic bodies present.

2. The process of repa ring a fertilizer which consists in oxi izing atmospheric nitro en and reactin u on a native hos hate F) containing iron and alumina With the crude products of such oxidation in sufficient quantity to decompose contained phosphates and v to combine with basic bodies present.

In testimony whereof I hereunto affix my signature in the presence of two Witnesses.

JOHANNES SCHLUTIUS.

, Witnesses:

HENRY HASPER, WoLnnMAR HAIL'PT. 

